From: kernel test robot <lkp@intel.com>
To: David Howells <dhowells@redhat.com>
Cc: oe-kbuild-all@lists.linux.dev
Subject: [dhowells-fs:netfs-lib 41/50] fs/cachefiles/io.c:552 __cachefiles_prepare_write() warn: unsigned 'pos' is never less than zero.
Date: Sun, 7 Jan 2024 11:50:28 +0800 [thread overview]
Message-ID: <202401071152.DbKqMQMu-lkp@intel.com> (raw)
tree: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git netfs-lib
head: 807c6d09cc99cbdf9933edfadcbaa8f0b856848d
commit: 7097c96411d22a1b3f6370dfd7eb2e3b7b83ff98 [41/50] cachefiles: Fix __cachefiles_prepare_write()
config: x86_64-randconfig-161-20240105 (https://download.01.org/0day-ci/archive/20240107/202401071152.DbKqMQMu-lkp@intel.com/config)
compiler: ClangBuiltLinux clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202401071152.DbKqMQMu-lkp@intel.com/
New smatch warnings:
fs/cachefiles/io.c:552 __cachefiles_prepare_write() warn: unsigned 'pos' is never less than zero.
Old smatch warnings:
fs/cachefiles/io.c:573 __cachefiles_prepare_write() warn: unsigned 'pos' is never less than zero.
vim +/pos +552 fs/cachefiles/io.c
8669247524c73e Jingbo Xu 2022-11-24 515
047487c947e8b9 David Howells 2021-10-21 516 /*
047487c947e8b9 David Howells 2021-10-21 517 * Prepare for a write to occur.
047487c947e8b9 David Howells 2021-10-21 518 */
a06fac1599c179 Jeffle Xu 2022-04-25 519 int __cachefiles_prepare_write(struct cachefiles_object *object,
a06fac1599c179 Jeffle Xu 2022-04-25 520 struct file *file,
e0ace6ca98bef0 David Howells 2023-11-22 521 loff_t *_start, size_t *_len, size_t upper_len,
047487c947e8b9 David Howells 2021-10-21 522 bool no_space_allocated_yet)
047487c947e8b9 David Howells 2021-10-21 523 {
047487c947e8b9 David Howells 2021-10-21 524 struct cachefiles_cache *cache = object->volume->cache;
7097c96411d22a David Howells 2024-01-02 525 unsigned long long start = *_start, pos;
7097c96411d22a David Howells 2024-01-02 526 size_t len = *_len;
047487c947e8b9 David Howells 2021-10-21 527 int ret;
047487c947e8b9 David Howells 2021-10-21 528
047487c947e8b9 David Howells 2021-10-21 529 /* Round to DIO size */
7097c96411d22a David Howells 2024-01-02 530 start = round_down(*_start, PAGE_SIZE);
7097c96411d22a David Howells 2024-01-02 531 if (start != *_start) {
7097c96411d22a David Howells 2024-01-02 532 kleave(" = -ENOBUFS [down]");
7097c96411d22a David Howells 2024-01-02 533 return -ENOBUFS;
7097c96411d22a David Howells 2024-01-02 534 }
7097c96411d22a David Howells 2024-01-02 535 if (*_len > upper_len) {
7097c96411d22a David Howells 2024-01-02 536 kleave(" = -ENOBUFS [up]");
e0ace6ca98bef0 David Howells 2023-11-22 537 return -ENOBUFS;
7097c96411d22a David Howells 2024-01-02 538 }
7097c96411d22a David Howells 2024-01-02 539
7097c96411d22a David Howells 2024-01-02 540 *_len = round_up(len, PAGE_SIZE);
047487c947e8b9 David Howells 2021-10-21 541
047487c947e8b9 David Howells 2021-10-21 542 /* We need to work out whether there's sufficient disk space to perform
047487c947e8b9 David Howells 2021-10-21 543 * the write - but we can skip that check if we have space already
047487c947e8b9 David Howells 2021-10-21 544 * allocated.
047487c947e8b9 David Howells 2021-10-21 545 */
047487c947e8b9 David Howells 2021-10-21 546 if (no_space_allocated_yet)
047487c947e8b9 David Howells 2021-10-21 547 goto check_space;
047487c947e8b9 David Howells 2021-10-21 548
047487c947e8b9 David Howells 2021-10-21 549 pos = cachefiles_inject_read_error();
047487c947e8b9 David Howells 2021-10-21 550 if (pos == 0)
7097c96411d22a David Howells 2024-01-02 551 pos = vfs_llseek(file, start, SEEK_DATA);
047487c947e8b9 David Howells 2021-10-21 @552 if (pos < 0 && pos >= (loff_t)-MAX_ERRNO) {
047487c947e8b9 David Howells 2021-10-21 553 if (pos == -ENXIO)
047487c947e8b9 David Howells 2021-10-21 554 goto check_space; /* Unallocated tail */
047487c947e8b9 David Howells 2021-10-21 555 trace_cachefiles_io_error(object, file_inode(file), pos,
047487c947e8b9 David Howells 2021-10-21 556 cachefiles_trace_seek_error);
047487c947e8b9 David Howells 2021-10-21 557 return pos;
047487c947e8b9 David Howells 2021-10-21 558 }
7097c96411d22a David Howells 2024-01-02 559 if (pos >= start + *_len)
047487c947e8b9 David Howells 2021-10-21 560 goto check_space; /* Unallocated region */
047487c947e8b9 David Howells 2021-10-21 561
047487c947e8b9 David Howells 2021-10-21 562 /* We have a block that's at least partially filled - if we're low on
047487c947e8b9 David Howells 2021-10-21 563 * space, we need to see if it's fully allocated. If it's not, we may
047487c947e8b9 David Howells 2021-10-21 564 * want to cull it.
047487c947e8b9 David Howells 2021-10-21 565 */
3929eca769b5a2 David Howells 2021-10-21 566 if (cachefiles_has_space(cache, 0, *_len / PAGE_SIZE,
3929eca769b5a2 David Howells 2021-10-21 567 cachefiles_has_space_check) == 0)
047487c947e8b9 David Howells 2021-10-21 568 return 0; /* Enough space to simply overwrite the whole block */
047487c947e8b9 David Howells 2021-10-21 569
047487c947e8b9 David Howells 2021-10-21 570 pos = cachefiles_inject_read_error();
047487c947e8b9 David Howells 2021-10-21 571 if (pos == 0)
7097c96411d22a David Howells 2024-01-02 572 pos = vfs_llseek(file, start, SEEK_HOLE);
047487c947e8b9 David Howells 2021-10-21 573 if (pos < 0 && pos >= (loff_t)-MAX_ERRNO) {
047487c947e8b9 David Howells 2021-10-21 574 trace_cachefiles_io_error(object, file_inode(file), pos,
047487c947e8b9 David Howells 2021-10-21 575 cachefiles_trace_seek_error);
047487c947e8b9 David Howells 2021-10-21 576 return pos;
047487c947e8b9 David Howells 2021-10-21 577 }
7097c96411d22a David Howells 2024-01-02 578 if (pos >= start + *_len)
047487c947e8b9 David Howells 2021-10-21 579 return 0; /* Fully allocated */
047487c947e8b9 David Howells 2021-10-21 580
047487c947e8b9 David Howells 2021-10-21 581 /* Partially allocated, but insufficient space: cull. */
3929eca769b5a2 David Howells 2021-10-21 582 fscache_count_no_write_space();
047487c947e8b9 David Howells 2021-10-21 583 ret = cachefiles_inject_remove_error();
047487c947e8b9 David Howells 2021-10-21 584 if (ret == 0)
047487c947e8b9 David Howells 2021-10-21 585 ret = vfs_fallocate(file, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
7097c96411d22a David Howells 2024-01-02 586 start, *_len);
047487c947e8b9 David Howells 2021-10-21 587 if (ret < 0) {
047487c947e8b9 David Howells 2021-10-21 588 trace_cachefiles_io_error(object, file_inode(file), ret,
047487c947e8b9 David Howells 2021-10-21 589 cachefiles_trace_fallocate_error);
047487c947e8b9 David Howells 2021-10-21 590 cachefiles_io_error_obj(object,
047487c947e8b9 David Howells 2021-10-21 591 "CacheFiles: fallocate failed (%d)\n", ret);
047487c947e8b9 David Howells 2021-10-21 592 ret = -EIO;
047487c947e8b9 David Howells 2021-10-21 593 }
047487c947e8b9 David Howells 2021-10-21 594
047487c947e8b9 David Howells 2021-10-21 595 return ret;
047487c947e8b9 David Howells 2021-10-21 596
047487c947e8b9 David Howells 2021-10-21 597 check_space:
3929eca769b5a2 David Howells 2021-10-21 598 return cachefiles_has_space(cache, 0, *_len / PAGE_SIZE,
3929eca769b5a2 David Howells 2021-10-21 599 cachefiles_has_space_for_write);
047487c947e8b9 David Howells 2021-10-21 600 }
047487c947e8b9 David Howells 2021-10-21 601
:::::: The code at line 552 was first introduced by commit
:::::: 047487c947e8b96b94579c3a33207bd4e266b4c6 cachefiles: Implement the I/O routines
:::::: TO: David Howells <dhowells@redhat.com>
:::::: CC: David Howells <dhowells@redhat.com>
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
reply other threads:[~2024-01-07 3:50 UTC|newest]
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